Rotary mercury circuit-breaker.



No. 792,195.l

PATENTBD JUNE 13, 1905.

A. F. CHRISTMAS.

ROTARY MERCURY CIRCUIT BREAKBR.

APPLICATION FILED AUG. 15.1904.

2 SHEETS-SHEET l.

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No. 792,195. PATENTED JUNE 13, 1905.

A. F. CHRISTMAS.

ROTARY MERCURY CIRCUIT BREAKER. APPLIGAT'ION HLED AUG.15,1904.

2 SHEETS-SHEET 2.

UNITED STATES .Patented June i3, 1905i.

PATENT OFFICE.

ADOLPH F. CHRISTMAS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF TWO-THIRDSTO FRANK R. MCFEATTERS, OF WILKINSBURG, PENN- SYLVAN IA.

ROTARY MERCURY CIRCUIT-BREAKER SPECIFICATION forming part of LettersPatent No. 792,195, dated June 13, 1905. Application filed August l5,1904. Serial No. 220,823.

To @ZZ wwnt it may concern..-

Be it known that I, ADoLPII F. CHRISTMAS, a resident of Pittsburg, inthe county of Allegheny and Stateof Pennsylvania, haveinvented a new anduseful Improvement in Rotary Mercury Circuit-Breakers; and I do herebydeclare the following to be a full, clear, and exact descriptionthereof.

My invention relates to circuit-interrupters, and more especially todevices of this character whereby heavy currents can be safely brokenand made repeatedly.

The object of the invention is to construct circuit makers and breakersof this character, so that the evil effects which result from the arcswhich are formed when a heavy current is broken are largely overcome.

Vith many translating devices--sucln for instance, as reciprocating'motors and the likeit is either necessary or desirable to break and makethe circuit at rapid intervals. With heavy commercial currents this isdiiiicult,

because the arcs which are formed detrimentally affect the terminals ofthe circuit-breaker and soon destroy the same and make the interrupteruseless. This difliculty has probably prevented the commercial use oftranslating devices which depend upon rapid interruptions of heavycommercial currents for their operation.

The object of the present invention is to provide a circuit-interrupterwhereby the foregoing defects are overcome.

To these ends the invention consists, generally stated, in providing aplurality of pairs of terminals in series with each other, together withmeans for separating said several pairs of terminals substantiallysimultaneously, whereby the voltage of the current is divided by thenumber of pairs of terminals and the arcs which are formed at theseparation of said terminals-are proportionately decreased in size.Preferably one of each pair of terminals will be a body of mercurycontained in apractically-sealed chamber, so that the arcs which arenecessarily formedwill expend themselves in volatilizing the mercury;

but as the latter is contained in a closed chamber it will immediatelycondense and again join the body of mercury.

The invention also comprises certain details of arrangement, such asproviding in connection with each body of Inercury a pair of contacts,those of the last contacts of the series being independent and connectedto different translating devices or to different windings of the samedevice and so arranged that the current will be alternately sent throughthe two translating devices or coils.

The invention also comprises certain details of construction, which willbe hereinafter described and claimed.

In the accompanying drawings, Figure lis a longitudinal section, partlyin side View, of my improved circuit-interrupter, showing in diagram thecircuits to which it is connected. Fig. 2 is a section on the line 2 2,Fig. 1; and Fig. 3 is a section on the line 3 3, Fig. 1.

My circuit-interrupter is constructed upon the principle that when anelectric circuit is simultaneously broken at two or more points inseries with each other the voltage of the current at each break will bethe voltage of the original current divided by the number of suchbreaks. To this end the interrupter comprises a plurality of pairs ofterminals in series with each other, together with means forsimultaneously separating said several pairs, as a result of which thearcs formed at the several breaks will be very small compared to an arcwhich would be formed by breaking the same current at a single point. Aninterrupter constructed on this principle may be embodied in a largevariety of forms. Preferably I employ mercury as one terminal of eachpair and inclose the same in a chamber,

so that the arcs which are formed will expend themselves in volatilizingthe mercury, which will again condense. The separation of these mercuryand their coacting metallic terminals may be brought about in anydesired manner. Preferably, however, the interrupter will be of therotary type, as thereby a more uniform movement can be imparted theretoand greater uniformity in the succession of interruptions and making ofthe current obtained.

As shown in the drawings, the interrupter comprises a suitable body 1,mounted on trunnions 2 in bearings 3, secured to an insulat-Y ing-base4L. This body can be rotated in any suitable way, such as connecting toone of the trunnions a belt-pulley 5 or other suitable means. The body 1is provided with a series of chambers 6, four such chambers being shown;but the number thereof may be varied within wide limits, two or moreembodying the principle ot' my invention. In each of these chambers iscontained a body of mercury 7, which,however,onl y partially tills thesame. Naturally in the rotation of the body the mercury will alwaysremain in the lower portions ofthe several chambers. Also projectinginto each chamber is a terminal or terminals 8, which in the rotation ofthe body come in contact with the mercury, thus establishing theelectrical circuit. In order to facilitate construction, each of thechambers 6 is built up of a pair of metallic shells 10, united in anysuitable manner, such as by the anges 11 and screws 12. The shells oladjacent chambers are separated from each other by a disk of insulation13, whereby electrical connection through the walls of said members iscompletely cut off. Each terminal 8 is provided with a stem 15, passingthrough a bushing ot' insulation 16, placed in the opening in the wallot' the particular chamber in which said terminal is located, and theend oi' said stem has a metallic connection through nuts 17 with thewalls ot' the adjacent chamber. Bearing against the outside ot' thelirst chamber 6 is a brush 18, which is connected with the positive poleof the source of electrical energy. As many terminals 8 will projectinto each chamber as the number of times it is desired to make and breakthe current at each rotation of the body. In the drawings said terminalsare shown double, so as to close the circuit twice during each rotationof the body. Into the last chamber ot' the series also project as manyterminals 2O as the number of times it is desired toA make and break thecircuit at each rotation of the body. Two such terminals are shown inthe drawings, said terminals being independent of each other, so as toconnect to two separate translating devices or to two coils of the sametranslating device. In case the translating device is only a single coilonly one of such terminals may be used, or the two terminals would beconnected together. These terminals 2O pass through bushings 21, ofinsulating material, set into the wall of the end chamber, and they areconnected one to a metallic ring 22 and the other to a similar ring 2?),which rings are suitably insulated from the bod y-bearings and from eachother by disks of insulation 24. Bearing against the ring 22 is a brushQ5 and bearing against the ring 23 is a similar brush 26, these cury.

readies brushes being connected to the two translatf ing devices or toseparate coils or' the same translating device.

The interrupter described may be used in any electrical circuit, asuitable one being shown in Fig. 1, in which the dynamo or othergenerator is shown at 28, having its positive main connected to thebrush 18 and having in its negative main two coils Q9 and 30, which mayrepresent independent translating devices or the two coils of areciprocating Inotor, these coils being connected by suitable wires tothe brushes 25 and 26, respectively.

The interrupter may be rotated by any suitable motor, and for thispurpose I have shown a small electricalmotor 81 belted to the pulley 5on the interrupter. This, however, is not necessary, as the interruptermay be driven Jfrom any independent motor or from a counter-shaft in thefactory or other convenient source.

In the operation of this interrupter the current coming from thegenerator will pass from the brush 18 to the body of mercury 7 in thefirst chamber. The mercury in the several chambers is always in contactwith some portion of the annular metallic walls of said chambers. In theoperation ot' the device when the body has been rotated so that theterminals 8 are in contact with the several bodies of mercury thecurrent coming from the generator will pass from the brush 18 to themercury in the iirst chamber, through the terminal 8 in that chamber andits stem to the metallic wall of the next chamber, thence to the body ofmercury therein, thence through the terminal 8 in that chamber and itsstem to the metallic wall ofthe next adjacent chamber, and so oncontinuously through the several chambers, and finally out of theinterrupter through whichever one of the terminals 2O is in contact withthe mercury in the last chamber, and thence to the translating device.As soon as the body has rotated sutliciently far to carry the terminals8 out of contact with the bodies of mercury the current will be brokenin each otl the several chambers of the interrupter. As a conseq uencethe voltage ofthe current at each break will be only such proportion ofthe entire voltage of the current as the number of interruptions bearsto unity. The arcs formed at each break will be proportionatelydecreased, and as a consequence heavy commercial currents of highvoltage can be safely broken and by a device of minimum size.Furthermore, the arcs will expend themselves in volatilizing themercury; but as the latter is contained in closed chambers it willcondense and again join the main body. It will be observed that thepositive terminal in each chamber is the body of mercury, so thatpractically no detrimental effects whatsoever will be produced on theterminals 8, but the entire energy ot' the arc will be expended involatilizing the mer- The bodies of mercury only partially IOO IIO

IIS

till the several chambers, and the terminals 8 merely sweep into contacttherewith. As a result the circuit Will be only momentarily closed andwith the full strength of the current being interrupted d uring thegreater portion of each revolution of the body 1. As a consequence thecoil of the translating device is given a strong' sudden energization;but the current will then cease, thus preventing the heating of thecoil, as would be the case if the current continued to flow to thetranslating device for a longer period. The principle is analogous tothat of the modern steam-engine, in which the steam is admitted to thecylinder for only a portion ofthe entire stroke of the piston. Theterminals 8 are of small section in their arcuate paths, as shown inFig. 3, so that the current Will be maintained only a short interval ot'time. This interval may be increased or decreased by varying the arcuateWidth of said terminals, and in this manner the period of energizationof the coil of the translating device can be regulated at will.

The details of construction of the circuitinterrupter may be variedwithin wide limits. It' desired, the several chambers containing themercury may be separated from each other by insulated Walls havingopenings therethrough through which the mercury may flow and come intocontact, thus forming the electrical connection between the severalchambers ot' the series, as shown in my Patent No. 773,121, October 25,1904, and described and claimed in my application, Serial No. 225,684,filed September 23, 1904.

1. A circuit-interrupter comprising a plurality of pairs of terminals inseries with each other, one terminal of each pair being merc'ury and theother being solid metal, and said terminals being so arranged that thecurrent passes from the mercury to the solid metallic terminal of eachpair, and means for separating said several pairs of terminalssubstantially simultaneously.

2. A circuit-interrupter comprising a plurality or' pairs or' terminalsin series With each other, one terminal of each pair being a mobileconducting medium contained ina closed chamber, and means for separatingsaid several pairs of terminals simultaneously.

3. A circuit-interrupter comprising a plurality of pairs or terminals inseries with each other, one terminal of each pair being mercurycontained in a closed chamber, and means for separating said severalpairs substantially simultaneously.

4. A circuit-interrupter comprising a body having' a plurality ofchambers therein, a pair of terminals exposed in each chamber, one atleast of said terminals being mercury, and constant electricalconnections to the mercury in one end chamber, said body being movableto bring the other terminals into and out of contact with the mercuryterminals.

v5. In a circuit-interrupter, the combination of a body having aplurality of chambers, a body of mercury in each chamber but onlypartially filling the same, electrical connections to the mercury in theirst chamber, terminals projecting into each chamber and havingelectrical connection to the mercury of the succeeding' chamber, andelectrical connections to the terminal projecting into the last chamber,said body being movable to bring the several terminals substantiallysimultaneously into and out ot' contact With the mercury bodies in saidchambers.

6. A circuit-interrupter comprising a rotatable body provided with aplurality ot' chambers, a body of mercury in each chamber but onlypartially lilling the same, permanent electrical connections to themercury in the rst chamber, terminals projecting into each chamber,permanent electrical connections to the terminal of the last chamber,and the terminals of each intermediate chamber being in permanentelectrical connection with the mercury of the succeeding chamber.

7. A circuit-interrupter comprising a rotatable body having a pluralityof chambers, a body of mercury in each chamber but only partiallyfilling the same, and a pair of metallic terminals exposed in eachchamber, the metallic terminals of the last chamber being independentand having separate electrical connections, and the terminals in eachintermediate chamber being in electrical connection with the mercury inthe succeeding chamber.

8. A circuit-interrupter comprising a rotatable body havinga pluralityof chambers With the walls formed in part of insulating material, a bodyof mercury in each chamber but only partially filling the same, annularmetallic portions exposed in each chamber and With which the mercury isin constant contact, electrical connections to the annular metallicportions of the {irst chamber', another metallic contact portion orportions exposed in each chamber at a point or points entirely thereinand arranged in the rotation of the body to come into contact atintervals with the mercury, electrical connections to the contactportion or portions of the last chamber, and electrical connections fromsuch contact portion IOO or portions ot' each intermediate chamber tocomposed of a plurality of' chambers having metallic walls and insulatedfrom each other, a body of mercury in each chamber but only partiallyfilling' the same, metallic contacts projecting into each chamber butinsulated from the Walls thereofl and having metallic connection withthe Walls of the succeeding chamber, the metallic contact of the lastchamber having an electrical connection thereto and a brush bearingagainst the metallic Wall of the first chamber.

ll. A circuit-interrupter comprising a body composed of a plurality ofchambers having metallic walls and insulated from each other, bearingsin which said body is rotatably mounted, a body of mercury in eachchamber but only partially filling the same, a brush bearing against theWall of the first chamber, a pair of independent terminals projectinginto the last chamber and insulated therefrom, a pair of contact-ringsto Which said terminals are independently connected, and a pair ofterminals projecting into each chamber but insulated from the wallsthereof and having' a metallic connection with the Walls of thesucceeding chamber.

1n testimony whereof I, the said ADoL'PH F. CHRISTMAS, have hereunto setmy hand. ADOLPH F. CHRlSTll/IAS. lVitnesses:

ROBERT C. ToTTEN, (i KREMER.

